One vertex per element, one color per generator, with an edge from x to x·s.
(2,3)(6,7)(19,23)(22,24)(25,26,30,31)(27,29,33,38)(28,35,36,32)(34,40,39,37)(10,13)(14,16)(17,18,21,20)(19,22,23,24)(26,31)(27,33)(28,36)(37,40)(1,2,5,3)(4,6,8,7)(9,10)(11,14)(12,13)(15,16)(17,19)(18,22)(20,24)(21,23)(25,27)(26,29)(28,34)(30,33)(31,38)(32,37)(35,40)(36,39)(1,3,5,2)(4,7,8,6)(25,28,30,36)(26,32,31,35)(27,34,33,39)(29,37,38,40)(1,4,5,8)(2,6,3,7)(9,11,12,15)(10,14,13,16)(17,20,21,18)(19,24,23,22)(25,29)(26,27)(28,37)(30,38)(31,33)(32,34)(35,39)(36,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.